Seat



A. F.- HICKMAN ET-AL 2,357,825

SEAT

Filed Oct. 16, 1941 Sept. 12; 1944.

4 Sheets-Sheet 1 48 1 IN ENTORS d%t& M4 BY M A62, 68 79 0,0 9, l 0

ATTORNEYi-Y Sept. 12, 1944. A. F. HICKMAN ET AL SEAT Filed Oct. 16, 19414 Sheets-Sheet 2 p A F. HICKMAN ET AL 72,357,825

SEAT

Filed Oct. 16, 1941 4 Sheets-Sheet 4 INVENTORS BY zT Patent d Sept.12,1944

SEAT

Albert 1-". Hickman, Eden, and Harold r; Pom.

Bnil'alo, N. Y., jasslgnors to Hickman Pneumatic Seat 00. Inc., Eden, N.Y., a corporation of New York Application October 16, 1941, Serial No.415,180

5 Claims.

This invention relates to a seat and more particularly to a resilientlymounted floating chair type seat particularly adapted for use invehicles, such as truck, busses, locomotive cabs, pleasure cars,airplanes and the like to cushion the driver or passengers againstobjectionable or harmful shocks, jars and virbations caused by thevehicle passing over uneven roads or rails or, in the case of airplanes,in landing. The floating chair type seat forming the subject of theinvention is, however, also available for use in boats or on vibratingstationary machinery or wherever a resiliently mounted seat isdesirable.

The present invention is of the same general type as the resilientlysuspended seats described in the Hickman United States Patents Nos.1,774,009 and 1,929,023, granted August 26, 1930, and October 3, 1933,respectively, and in the copending Hickman applications for patent, Ser.Nos. 373,273 and 387,642, filed January 6, 1941, and April 9, 1941,respectively, the latter of which became Patent No. 2,300,422 on Nov. 3,1942.

It is the principal object of this invention to provide a springsuspension for supporting a chair type'seat which has thee superior ridecharacteristics of the seats shown in the said patents and copendingapplications and at the same time is of such design that the movingparts of the spring suspension can be arranged under the plane of theseat part of the chair frame thereby avoiding the necessity of providing.a subframe with a back part carrying a part of the spring suspension.

Another object of the invention is to provide such a resiliently mountedfloating chair type s'eat having a spring suspension capable of beingarranged below the plane of the seat and which provides the maximumvertical movement. of the seat frame without interference with the partsand which adequately prevents objectionable jars and vibrations of allfrequencies from being transmitted to the body of the seated passengeror operator of the vehicle and in whichthe spring suspension. yieldinglyprevents undue movement of the seat and has rapid loading and unloadingcharacteristics beyond the normal range of movement of the seat.

Another object of the invention is to provide such a resiliently mountedfloating chair type seat having a spring suspension capable of beingarranged below the plane of theseat and in which the spring suspensioncontrols the direction of movement of the seat frame.

Another object isto provide such a spring suspension in which thespringing means is in the form of inexpensive metal springs.

Another object is to provide such a resilientlly mounted floating chairtype seat which is made of simple parts and of a construction adapted tomass production and in which seats of different sizes can be made withthe simple alteration in length of only a few parts of the mechanism.

Another object is to provide such a spring suspension for a chair typeseat which is strong and durable in construction and will operatesmoothly and easily without damage; which is light in weight to permitits use in airplanes and in which the moving parts are adequatelyguarded so that there is no danger of the passenger suffering injurywhile riding on the seat.

Another object of the invention is to provide such a spring suspensionfor a chair frame in which the support for the spring suspension can bein the form of a simple casting and can be readily attached to anupright post or the like.

Another object of the invention is to provide such a suspension for afloating chair type seat in which the seat can be of relatively lightand flexible construction, the operation of the spring suspension notbeing dependent upon the rigidity of the seat frame.

Another object of the invention is to provide such a floating chair typeseat in which the chair frame can be in the form of a piece of bentplywood, the spring suspension being capable of being attached directlyto the plywood and the cushioning likewise being capable of beingattached directly to the plywood thereby to employ a material nowavailable in greater quantities in a low cost resiliently mountedfloating chair type seat.

Another aim is to provide such a floating chair type seat in which thechair frame can be made of spring metal so as to provide an inherentlyresilient back and reduce the amount of spring required in the backcushion.

Another object of the invention is to provide such a floating chair typeseat in which the front and sides of the seat can be substantiallycompletely encased in the leather or fabric with which the seat cushionsare upholstered thereby to render the seat neat and trim in appearance.

Another aim is to provide such. a floating chair type seat which is freefrom lateral projections thereby permitting the seats to be arrangedside by side substantially in contact with one another and therebypermit the seating space with in all standard cabs to be filled with theminimum number of sizes of seats.

Other objects of the invention are to provide such a floating chair typeseat which is simple and inexpensive in construction, is composed of fewparts which are not liable to get out of order, which does not requirefrequent servicing and which will not develop objectionable squeaks andnoises even when subjected to conditions of severe and constant use.

In the accompanying drawings:

Fig. 1 is a side elevation partly in section of one form of resilientlymounts chair type seat embodying our invention.

Fig. 2 is a horizontal section, taken on line 2-2, Fig. 1.

Fig. 3 is a fragmentary, enlarged, vertical section, taken on line 3-3,Fig. 1.

Fig. 4 is a fragmentary, enlarged, vertical section, taken on line 4-4,Fig. 2.

Fig. 5 is a view similar to Fig. 1 showing a modifled form of ourinvention.

Fig. 6 is a view similar to Figs. 1 and 5 showing a further modifiedform of our invention.

Fig. 7 is a fragmentary horizontal section, taken on line Fig. 6.

Fig. 8 is an enlarged, fragmentary, horizontal section, taken on line6-8, Fig. '7.

- side bars 25 in any suitable manner.

Fig. 9 is a view similar to Figs. 1, 5 and 6 showing a further modifiedform of our invention.

Fig. 10 is a fragmentary, horizontal section, taken on line ill-40, Fig.9.

Fig. 11 is an enlarged, fragmentary, vertical section, taken through oneof the bearings I shown in Figs. 9 and 10.

Fig. 12 is a fragmentary, horizontal section, taken on line |2l2, Fig.11.

In the various forms of the invention illustrated the seat is shown ascomprising a cushioned chair-like seat frame having a back part which isrelatively rigidly connected with a seat frame, although springiness canbe provided between the two parts, a support or subframe adapted to besecured to the body of the vehicle and a resilient spring suspensionbetween the chair-like seat frame and the support or subframe and whichresiliently supports the chairlike seat frame and permits resilient,guided movement of the seat frame relative to the subframe. While theseat frame is shown as being made in the form of a rigid structure itwill be understood that if desired the back part could be adiustablysecured to the seat part so as to permit of adjusting the back part todifferent reclining positions.

In the form of the invention shown in Figs. 1-4 the cushioned chairframe or seat frame is shown as comprising a seat part. indicatedgenerally at I5, and a backpart indicated generally at l6, which isrigidly connected with the seat part l5. The frame of the seat part isshown as comprising a pair of side bars l1 in the form of angle irons,these angle irons being arranged so that their upper flanges l8 opposeeach other and are arranged in the same horizontal plane and thevertical flanges I! of these bars extending downwardly from the outersides of these bars. At their front ends the side bars I! are connectedby a cross bar 26 which is also preferably in the form .of an armle ironand the ends of this cross bar 20 being shown as welded to theundersides of the horizontal flanges l8 of the side bars IT. The

rear ends of the side bars I! are connected by a rearwardly asubstantial distance beyond the cross bar 2 I, as indicated at 22, andthe horizontal flange of each of these extensions 22 is shown asbeingput away as indicated at 23.

The back part I6 is shown as comprising two side bars 25 in the form ofangle irons, these bars being arranged so that their flanges 26 opposeeach other and are arranged in the same plane, the other flanges 21 ofthese bars extending rearwardly. The lower ends of the side bars 25 ofthe back part Hi can be welded to the rear ends of the side bars I! ofthe seat frame l5 and to the opposite ends of the cross bar 2| in anysuitable manner and the side bars 25 of the back part ii of the seatframe are also shown as connected by cross bars 28 and 29 which can bewelded or otherwise secured to the opposed flanges 26 of the The backpart I6 is also shown as braced by a pair of diagonal braces or struts30, each of which is welded at its upper end to the corresponding sidebar 25 of the back part l6 of the chair frame and at its lower end tothe corresponding extension 22 of the seat part of the seat frame. Thesupport or subframe, indicated generally at 35, is shown as comprisingtwo wooden bars 36 which extend fore and aft in spaced relation to eachother and are adapted to be secured to the body of the vehicle in anysuitable manner (not shown). These wooden bars 36 are shown assupporting a sheet metal cross plate 31 which is provided with upturnedflanges 38 at its front and rear edges, these flanges being adapted toembrace and retain the lower coils of a plurality of helical compressionsprings 39 which form the major resilient resistance to the movement ofthe chair frame relative to the subframe. The coil springs 39 can beprovided in any desired number and are shown as held against lateraldisplacement by a plurality of lips 40 which are struck upwardly fromthe center of the supporting, plate 31 in position to embrace the lowercoils of the helical compression springs 39. The upper ends of the coilsof the helical compression springs are similarly secured to a crossplate 4|, the ends of which can be welded to the undersides of the upperflanges l8 of the side bars I! of the seat frame and this plate beingformed with downturned flanges 42 at its front and rear edges to preventfore and aft displacement of the upper coils of the springs 39 and beingalso provided with central downturned lips or fingers 43 which arearranged to embrace the upper coils of these springs to prevent theirsidewise displacement.

The chair frame is guided to move in a generally vertical direction by apair of yokes which are preferably constructed and secured to the woodenbars 36 of the subframe and the side bars I! of the seat part l5 of theseat frame as follows:

The rear ends of the side bars I! of the seat part l5 of the seat frameare secured to the rear ends of the wooden bars 36 of the subframe by ayoke 45 which is in the form of a rod bent to provide a cross rod 46 anda pair of forwardly projecting end arms 41 to the end of each of whichis secured a tubular eye 43, these tubular eyes being arranged in linewith each other and parallel with the rod 46. Each of these eyesembraces the shank of a. carriage bolt 50, these bolts being secured tothe vertical side flanges IQ of the side bars I! of the chair frame andprojecting inwardly therefrom, as best shown in Fig. 3. A metal sleeveor bushing 5| is pressed on the shank of each bolt 50 and a resilientpivotal connection between each eye 43 and its bolt 50 is provided by2,357,325 3 of the two yokes 45. This connecting rod "is a resilientbushing 52 of resilient rubber-like material, this bushing being held infirm engagement with the corresponding eye 48 and the sleeve or bushing5| press fltted on the shank of the corresponding carriage bolt 68 by anut 63 and washer 54 secured to the threaded inner end of the bolt 68.The extent of the compression of each rubber bushing 62 in the spacebetween its eye 48 and the metal bushing 5i is determined by the lengthof this metal bushing 5 I, the washer 64 seating against the end of thismetal bushing 51 and preventing further compression of the rubberbushing 62. The extent of the compression of the rubber bushing ispreferably such that the rubber firmly adheres to both the interior faceof the eye 48 and the exterior face of the metal bushing 5| and isstressed and distorted as the eye oscillates about the bolt 50 as anaxis thereby to add to the resilient resistance of the helicalcompression springs 39 in resisting the movement of the seat framerelative to the subframe.

A pair of spaced, generally similar rubberbushed bearings 66 is shown asconnecting the cross rod 46 of the rear yoke 45 with each of the woodenbars 36 of the subframe. As best shown in Fig. 4, each of these bearings66 comprises a half bearing made of a wooden block 6| having ahorizontally extending half round socket for the reception of a bushing62 of resilient yielding material, such as rubber. This bushingsurrounds the corresponding part of the cross rod 46 of the yoke and isfirmly held in engagement therewith and with the socket in the hall.bearing block 6| by a half bearing plate 63 which is formed at itscenter to provide a horizontally extending socket embracing the upperhalf of the rubber bushing 62. The half bearing plate 63 and the halfhearing block of each bearing 60 are secured to each other and to therear end of the corresponding wooden bar 36 by a pair of screws 64. Therubber bushings 62 are tightly confined between the two half bearings sothat the rubber is flexed and distorted to provide the necessary rockingmovement of the rear yoke.

The cross bar 46 of the yoke 45 is also shown as provided with a pair ofclosely spaced crank arms 65 which. are shown as being welded to thecross bar 46 and can be arranged at any desired location along thelength of this cross rod. These crank arms, for a purpose which willpresently appear, project in a different direction from the end arms 41of the yoke and are shown as normally projecting downwardly atapproximately a 90 angle to the end arms 41, although the relativeangularity of these arms and the length of the crank arms 65 is notcritical. The free ends of the pair of crank arms 65 carry a bolt 66which, between the crank arms 65 carries a rubber bushing 6'! to providea rubber hushed, pivotal connection for a purpose which will presentlyappear.

At its front end, the seat part iii of the seat frame has suitablysecured thereto a pair of depending brackets or ars 68, each of thesebrackets being shown as welded to the corresponding side bar I! of theseat part l5 of the seat frame. The brackets 68 of the seat frame aresecured to the front ends of the wooden bars 36 of the subframe by ayoke and bearings which are identical with the yoke 45 and bearingssupporting the rear of the seat frame and hence the same referencenumerals have been applied.

An important feature of the present invention resides in the provisionof a connecting rod between the pivot bolts 66 of the crank arms 65,

shown as being formed at its opposite ends to proents and patentapplications.

iii

vide a pair of eyes II which tightly embrace the rubber bushings 61 atthe ends of the crank arms of the two yokes so that the rubber bushingsare stressed and flexed as the yokes oscillate. I With the arrangementof the yokes 45, as shown, the connecting rod 18 is necessary to preventthe yokes from locking as they swing into line with one another. Thus,in the absence of the connecting rod 18, when the end arms 41 of the twoyokes 45, swing into line with each other (in a horizontal plane with tharrangement shown) one yoke would be capable of turning clockwise whilethe other yoke would be capable of turning counterclockwise. Suchopposite movement of the yokes would throw the seat to an inoperativecocked position and the parts would look in this position. Bytheprovision of the cranks 65 and the connecting rod 10, it is insured thatthe yokes rotate at all times uniformly in the same direction and hencethere is no possibility of the sus-- pension locking in any condition ofoperation. By the provision of the conencting rod 18 it will be seenthat the yokes can be arranged generally in horizontal alinement andbelow the plane of the seat part of the seat frame instead of one abovethe other as in the aforesaid Hickman pat- The use of the connecting rod18 thereby eliminates the. necessity for a back part for the subframeand enables the substitution of the two bars 36 for the more complicatedsubframe structure required by the aforesaid Hickman patents and patentapplications. 7

In order to enclose the space between the subframe and the seat part ofthe seat frame at the front and sides thereof and hence improve theappearance of the seat as a whole; the two wooden load carrying bars 36of the subframeare shown as secured to a sheet of plywood 15 to whicharesecured marginal front, rear and side bars l6, l1, l8 and 13,respectively, these marginal bars being shown as secured to the upperface of the sheet 15 of plywood and as being rounded at their outercorners. The seat cushion is shown as comprising a sheet of plywood 66which can be bolted to the side bars H of the seat frame by bolts 8| andis shown as carrying a cushion 82 composed of sponge rubber, rubberizedhair or like soft, resilient material suitable for a seat cushion andhaving the neces ary durability to stand up under the severe serviceconditions to which seats of this character are subjected. A sheet 83 offabric or the like is shown as being interposed between the rubberizedhair or sponge rubber cushion 82 and the plywood sheet 86 and the frontand rear edges of this sheet of fabric 83 is shown as projecting fromunder the cushion 82. To the rear projecting edge of this sheet 83 offabric is also secured the rear edge of the fabric, leather orleatheroid cover 85 for the seat cushion 82, this preferably being 'bytacks or screws which anchor in the rear ed'te of the sheet of plywood86 so that these fastenings also serve to hold the rear edge of the seatcushion 82 to the plywood panel 88. 83 of upholstery fabric extends overthe top of the sponge rubber or-rubberized hair cushion 82 and in frontof the cushion extends downwardly, as indicated at 86, and is securedboth to the forwardly projecting edge of the under piece of fabric 83,as indicated at 81, by sewing and also to the front marginal bar 16 ofthe subframeby tacks 88 or in any other suitable manner. The

The piece piece 89 of upholstery fabric is also formed'to provide sidepanels 89 which extend downwardly alongside the sponge rubber orrubberized hair seat cushion 82 and are secured at their lower.

. very materially add to the appearance of the seat.

The back of the seat frame can be provided with a spring filled backcushion 90 of any suitable form, this back cushion preferably being of.the vented type, as discussed in the Hickman patent application Ser.No. 373,273 and being shown as secured to the back part I8 of the seatframe by bolts 9| which anchor in the cross bars 28 and 29 of this backpart of the seat frame.

In the operation of the form of the invention shown in Figs. 1-4, theseat is shown in its normally unloaded position in which the arms 41 ofthe two yokes 45 are elevated slightly above the horizontal and thefront and side panels 88, 89 of the upholstery fabric for the seatcushion and which are secured along their lower edges to the subframeare fully extended. When the rider sits upon the seat, the arms 41 ofthe two yokes are brought to a generally horizontal normal position andthe weight of the driver is supported by the helical compression springs39 as well as by the eight rubber bushings 52, 62 which pivotallyconnect the two yokes 45 with the seat frame and with the two woodenbars 38 of the subframe. Additional resilient support is provided by thetwo rubber bushings 01 which connect the ends of the connecting rod Iwith the two yokes. When the vehicle frame is moved upwardly uponencountering a bump in the road, the weight of the occupant of the seatmoves the seat frame downwardly, this movement of the seat frame beingdownwardly and rearwardly, as determined by the arms 41 of the yokes land the seat frame being held a ainst tipping forwardly or backwardlyduring this downward movement. Since the arms 'of the two yokes connectwith opposite sides of the seat frame there is also no tendency for theseat frame to tip or twist in its downward movement. Upon reboundmovement of the occupant and the seat frame the seat frame movesforwardly and upwardly to its normal loaded position in which the arms41 of the seat frame are arranged in a horizontal-plane. In thisposition the arms of the two yokes are arranged in the same horizontalplane and in this position the arms of the front yoke would normally befree to rotate in one direction while the arms of the other yoke wouldbe free to rotate in the opposite direction. This would, of course,cause the seat frame to lurch to a forwardly or backwardly tippedposition and also the parts would become locked in this lurched positionof the seat frame and render the suspension wholly useless. To avoidthis, the connecting rod I0 is provided, this connecting rod beingsecured to the crank arms 85 of the two yokesand these crank arms 85being set at a different angle from the end arms 41 of these yokes. Byvirtue of this interconnection of the two yokes by an independentconnecting rod I0, the yokes are always compelled to rotate in the samedirection; so that even when their end arms 41 are arranged in the sameplane there is no danger of these yokes ronecting rod I9 both yokes canbe arranged below the plane of the seat thereby permitting the subframeto be composed of the two bars 88 instead of a more complicatedstructure, including a back support which would be necessary if the twoyokes were required to be arranged one above the other, as shown in thesaid Hickman patents I of the invention shown in Fig. 5 is shown astating so as to throw the seat to a cooked position in which the partsinterlock and render the composed of two arms of spring steel. the lowerpart of which is bent horizontally so as to be capable of being boltedto the upper horizontal flanges of the side bars ll of the seat I frameby bolts 96 or in any other suitable manner. The lower part of eachspring back 99 can be reinforced by a separate spring leaf 9! which canalso be secured to the seat part of the chair frame by the bolts 98 asillustrated. I The back cushion 98 can be of any suitable constructionand can be secured to the spring back 95 by bolts 99 or in any othersuitable manner. By providing inherent resilience in the back of theseat frame, the back cushion 98 need not be spring loaded but can becomposed of the same upholstered sponge rubber or rubberized hair asthesheet metal back part I00, the sides of which are bent to provide sidesIM and depending side aprons I02. The seat part of the chair frame isshown as comprising a sheet of metal I03 which can be welded at itsedges to the back part I00 and sides IOI of the seat frame and can beformed at its front to provide a depending flange or apron I 04 whichcan be welded to the front vertical edges of the side aprons I02. Thechair frame can be upholstered with the usual seat cushion I 05 and backcushion I06 which can be made removable if desired. The bucket typechair frame preferably is not provided with a depending apron along itsrear side.

' This bucket type of seat is shown as supported on the post IIO of avehicle, such as a bus, by a subframe or bracket indicated generally atIII which is shown as being in the form of a casting formed to provide,at its rear end, a split tubular portion or pair of Jaws II2 which areadapted to be drawn into engagement with the post Ill by means of boltsH9. The casting or subframe I I I is shown as formed at its rear end toprovide a pair of laterally extending arms III, the extremity of each ofwhich is formed to provide a vertical riser 5. At its front end thecasting or subframe III is shown asprovided at its opposite sides withsimilar risers II8, the risers II at each side being shown as arrangeddirectly in front of'the corresponding riser IIB. 'Adiacent its centerthe subframe or casting III is shown as being formed to provide aplurality of bosses or lips I", which lips or bosses are arranged toembrace and anchor the lower coils of one or more helical compressionsprings H8. The upper ends of these springs II3 are similarly embracedand held by a plurality of flanges or fingers II3 punched downwardlyfrom the seat part I03 of the metal seat frame.

The chair frame is guided to move in a generally vertical direction by apair of yokes which are preferably constructed and secured to thesubframe III and the chair frame as follows:

The apron or depending flange I04 is connected to the upper risers II5of the subframe or casting III by a yoke I which is in the form of a rodbent to provide a cross rod I2I and a pair of forwardly projecting armsI22 each of which terminates in an inward extension I23 arrangedparallel with the cross rod I2I. At its center the cross rod I 2I isformed to provide a crank I24, this crank being set at a different anglefrom the arms I22, the crank being shown as extending downwardly andforwardly when the arms I22 are in a horizontal position. Each of theinward extensions I23 is secured to the front flange or apron I04 of theseat frame by a rubber bushed bearing, indicated generally at I and eachend of the cross rod I2I is connected to the corresponding riser II6 ofthe subframe or casting III by a similar rubber busher bearing. As theserubber bushed bearings are identical in construction a description ofone will be deemed to apply toall.

As best shown in Fig. 11, each of these bearings comprises a halfbearing made of a wooden block I3I having a horizontally extending halfround socket for the reception of a bushing I32 of resilient yieldingmaterial, such as rubber. This bushing surrounds the correspondinginward extension I23 of the adjacent arm I 22 of the yoke and is heldfirmly in engagement with the extension of this yoke and with the socketin the half bearing I 3i by a half bearing plate I33 which is formed atits center to provide a horizontally extending socket embracing the rearhalfof the rubber bushing I32. The rear half bearin plate I33 and thehalf bearing block I3I are secured to each other and to the front apronor flange I04 of the seat frame by a pair of bolts I34. The upperbushings I32 are tightly confined between the two half bearings so thatthe rubber is flexed and distorted to provide the necessary rockingmovement of the front yoke I20.

At its rear, the seat part I03 of the seat frame has suitably securedthereto a pair of depending brackets I35 of any suitable form, each ofthese brackets being arranged immediately in front of the correspondingriser H5 at the rear of the subframe or casting III. The brackets I35 ofthe seat frame are secured to the risers N5 of the subframe by a. yokewhich is identical with the yoke I 20 supporting the front of the seatframe and hence the same reference numerals have been applied.

As with the form of the invention shown in Figs. 1-3, in order toprevent the yokes I20 from looking when their arms I22 swing into linewith one another, the cranks I24 of these yokes are connected by aconnecting rod I40. For this purpose each of the crank arms I24 isprovided with a rubber bushing MI and the connecting rod I is made oftwo identical halves I43, each of which is formed at its opposite endsto provide half round sockets I44 embracing the corresponding rubberbushings I4 I. The two halves I43 of the connecting rod I40 are securedtogether and the ends I44 are held in tight clamping engagement with therubber bushings MI by bolts I45. It will be seen that by thisarrangement the rubber bushings I4I add to the resilience provided bythe two rubber bushings I32 and the springs II 8-also serve as thepivotal means for connecting. the connecting rod I40 with the two cranksI24 of the front and rear yokes I20. By the provision of the cranks I24in these yokes and by the provision of the connecting rod- I40connecting these crank arms, it is insured that the yokes rotate at alltimes uniformly in the same direction and hence there is no possibilityof the suspension locking under any condition of operation.

In the form of the invention shown in Figs. 942, the frame of the seatis shown as composed of a piece I50 of plywood which is bent toresiliently provide a seat part I5I, a back part I52, a curved part I53connecting the seat part with the back part, and a front dependingflange I54. The seat part I5I is upholstered by a seat cushion I55, theupholstery of which can be directly secured to the plywood by tacks orin any other suitable'manner and similarly the back cushion I56 can bedirectly tacked or otherwise secured to the back part I52 of the plywoodframe. The seat part I5I preferably extends upwardly from the curve I53so as to provide adequate space for the operation of the front yoke ofthe seat frame as hereinafter described. The curved part I53 of the seatframe is preferably reinforced by inner and outer blocks I58 and I59.the outer block I59 also serving as the anchorage for the two rubberbushed bearings for the rear yoke as hereinafter described. The seat isshown as supported from a base I60 on U-shaped brackets IGI by means ofa double yoke suspension identical with that shown in Figs. 6-8.Accordingly, the same reference numerals have been applied and thedescription is not repeated.

In the event that additional support is desired for the back part I 52of the seat frame, this back part can be connected, as shown, to arising part I62 of the base I60 by a yoke, indicated at I20a, this yokebeing connected by rubber bushed bearings to the back part I52 of theseat frame and to the vertical part I62 of the support. This yoke I20;is identical in construction with the yokes I20 except that it is notprovided with a crank arm and the bearings for this yoke are identicalwith the bearings for the yokes I 20. Accordingly, the same referencenumerals have been applied to the yoke I20a and its bearings anddistinguished by the sufllx a.

It will be seen that in the form of the invention illustrated in Figs.9-12 the same advantages are obtained as in the spring suspensions ofthe other forms of the invention and further that the seat frame can becomposed of a piece of preformed plywood and supported with suificientrigidity to stand up under conditions of severe and constant use. Itwill further be seen that by forming the seat part I5I of the plywoodseat frame to extend upwardly from its curve I53, suiflcient space isafforded at the front of the seat for the full operation of the frontyoke 45.

From the'foregoing it-will be seen that the present invention provides afloating chair type seat of simple and inexpensive construction. in

with all vehicles, particularly in absorbing Jars and vibrations of allviolence and frequencies and in moving in a substantially straight linedownwardly and rearwardly from its normally loaded position, thereby toavoid any lurching or undesired action of the seat. Further, the seat isso constructed as to have a very small vertical movement of its chairframe and at the same time is capable of adequately absorbing violentjars or shocks, thereby permitting'the use of the seat in the extremelyconfined space permitted in a passenger bus, railroad car or airplane.It will further be seen that with the arrangement of the springsuspension below the plane of the seat, the necessity for an elaboratesubframe is avoided and an economy is effected. The seat also has nolateral projections so that the seats can be placed side by side withoutinterfering with each other, this permitting seats of, say 16 inch and20 inch widths to meet practically all cab widths and arrangementsdesired. The arrangement of the suspension below the plane of the seatalso permits the space between the seat frame and the subframe to becompletely concealed by carrying the upholstery fabric from the seatcushions directly down to the subframe.

We claim as our invention:

1. A unitary self-contained seat structure, including a subframe, achair frame comprising a seat part arranged in closely spaced relationto and above said subframe and a back part connected with said seatpart, means interposed between said subframe and said chair frame forguiding said chair frame in its vertical movements toward and from saidsubframe and preventing said chair frame from. tipping and twisting,comprising a yoke having a horizontal cross part extending parallelwiththe front part of said chair frame and a pair of spaced, generallyparallel arms fast to said cross part and arranged within the confinesof said chair frame and extending laterally outward from said cross'part in a generally horizontal plane, means pivotally connecting theopposite ends of said horizontal cross part of said yoke to one of saidframes adjacent the front end thereof, means pivotally connecting thearms of said yoke to the other of said frames adjacent the front endthereof, a seat mounted on said seat part of said chair frame to extendsubstantially the full width thereof and being inclined forwardly and'upwardly to provide clearance for the movement of said yoke, a secondyoke arranged rearwardly of said seat and having a horizontal cross partextending parallel with the front pa t of said chair frame and a pair ofspaced, generally parallelarms fast to said cross part and arrangedwithin the confines of said chair frame and extending laterally outwardfrom said cross part in a generally horizontal plane, means pivotallyconnecting the opposite ends of said horizontal cross part of saidsecond yoke to one of said frames adjacent the rear end thereof, meanspivotally connecting the arms of said second yoke to the other of saidframes adjacent the rear end thereof, the arrangement of said secondyoke rearwardly of the depressed end of said seat preventinginterference with the free movement of said second yoke when said seatframe is fully deconnecting the outer ends of said cranks to compel thearms of both yokes to oscillate in unison in the same direction, andspring means directly interposed between said frames and restrainingmovement of said chairframe relative to said subframe.

2. A unitary self-containedseat structure, including a subframe, agenerally horizontal seat frame arranged in closely spaced relation toand above said subframe, means interposed between said subframe and saidseat fram for guiding said seat frame in its vertical movements andpreventing said seat frame from tipping and twisting, comprising a pairof parallel yokes arrangedone in advance of the other and each having ahorizontal cross part extending parallel with the front part of the seatframe and a pair of spaced, normally horizontal, generally parallel armsof substantially the same effective length fast to said cross part andextending laterally outward therefrom, means pivotally connecting theopposit ends of said horizontal cross part of each yoke to one of saidframes, means pivotally connecting the said arms of each yoke to theother of said frames and means interposed between and independent ofsaid seat frame and subframe and interconnecting sad yokes compel saidarms of both yokes to oscillate in unison in the same direction, and asingle row of helical compression springs interposed between saidsubframe and said seat frame and arranged under the bottom part of saidseat frame between said yokes to extend parallel with said front partofsaid seat frame.

3. A unitary, self-contained seat structure, including a subframe, achair frame comprising a seat part arranged in closely spaced relationto and above said subframe and a back part connected with said seatpart, means interposed between said subframe and said chair frame forguiding said chair frame in its vertical movements and preventing saidchair frame from tip-' ping and twisting, comprising a pair of parallelyokes each having a horizontal cross part extending parallel with thefront part of the chair frame and a pair of spaced, generally parallelarms fast to said cross part and extending laterally outward therefrom,means pivotally connecting the opposite ends of said horizontal crosspart of each yoke to one of said frames, means pivotally connecting eachof the said arms of each yoke to the other of said frames and a crankfast to the horizontal cross part of each of said yokes, said cranksbeing shorter in length than said arms and being arranged generallyparallel with each other and extending in a different direction fromsaid arms, a connecting rod pivotally connecting the outer ends of saidcrank to compel said arms of both yokes to oscillate in unison in thesame direction, and springs each having one end seated on said subframeand its other end connected with said seat frame and resilientlyrestraining movement of said chair frame relative to said subframe.

4. A unitary, self-contained seat structure, including a pair oftransversely spaced, generally horizontal supporting bars extendingfore-andaft and forming a subframe, a generally hori- .zontal seat framearranged in closely spaced re transversely of said supporting bars andjournaled on one of said frames adjacent the rear end thereof and havingspaced, forwardly extending arms of substantially the same effectivelength pivotally connected to the other of said frames adjacent the rearend thereof, a crank fast to the horizontal cross part of each of saidyokes, said cranks being shorter in length than said arms and beingarrangedgenerally parallel with each other and extending inadifferent direction from said arms, and a connecting rod pivotally connecting theouter ends of said cranks to compel said arms of both yokes to oscillatein unison in the same direction, and springs each having one end seatedon said subframe and its other end connected with said scat frame andresiliently restraining movement of said seat frame relative to saidsubframe, said yokes, cranks, connecting rod and springs all beingarranged above the base of said horizontal supporting bars in allpositions thereof.

5. A unitary, self-contained seat structure, including a subframe, agenerally horizontal seat frame arranged in closely spaced relation toand above said subframe and including side bars extending fore-and-aft,means interposed between said subframe and said seat frame for guidingsaid seat frame in its vertical movement and preventing said seat framefrom tipping and twisting, comprising a yoke having a horizontal crosspart extending transversely of said subframe and joumaled at itsopposite ends thereon adjacent the front end thereof and a pair ofspaced arms of substantially the same effective length fast to saidcross part and extending forwardly therefrom and each pivotallyconnected to the corresponding side bar of said seat frame adjacent thefront end thereof, a seat mounted on and extending across the spacebetween said side bars of said seat frame and being inclined forwardlyand upwardly to provide clearance for the movement of said yoke, asecond yoke arranged rearwardly of said seat and having a horizontalcross part extending transversely of said subframe and journaled at itsopposite ends thereon and a pair of spaced arms of substantially thesame effective length fast to the cross part of said second yoke andextending forwardly therefrom and each pivotally connected to the rearend of the corresponding side bar of said seat frame, the arrangement ofsaid second yoke rearwardly of said seat preventing interference withthe free movement of said second yoke when said seat frame is fullydepressed, a crank fast to the horizontal cross part of each of saidyokes, said cranks being arranged generally parallel with each other andextending in a different direction from said arms and a connecting rodpivotally connecting the outer ends of said cranks to compel said armsof both yokes to oscillate in unison in the same direction, and springseach having one end seated on said subframe and its other end connectedwith said seat fram and resiliently restraining movement of said seatframe relative to said subframe, said yokes, cranks, connecting rod andsprings all being arranged above the base of said subframe in allpositions thereof.

ALBERT F. HICKMAN. HAROLD I. POPP.

